The SET-RPLA is a commercially available kit for the detection of staphyloccal enterotoxins in foods. Previous reports have shown that non-specific reactions occur on use of the kit with cheeses and thereby restrict its use. In this study a variety of dairy products were tested and non-specific reactions were found to be associated with those products rennetted during manufacture. These reactions can be obviated by addition of 10 mM sodium hexametaphosphate to the diluent provided in the kit, without affecting the ability to detect staphyloccal enterotoxins in dairy products. The sensitivity of the SET-RPLA was demonstrated to be 0.25 ng/ml.